Field of the Invention
The present invention relates to a light emission control device, a control method therefor, a storage medium storing a control program therefor, and an image pickup apparatus with the light emission control device, and in particular, relates to emission control for controlling a light emission unit to emit light in an image pickup apparatus.
Description of the Related Art
There is a known pre-emission system that performs pre-emission prior to main emission as an emission control performed when photographing with emitting a light emitting unit of a lighting device or a light emitting unit (referred to as an electric flash) of an image pickup apparatus. In the pre-emission system, an image pickup apparatus obtains an image by photographing an object without emitting the electric flash first (the image is referred to as a non-emission image).
Next, the image pickup apparatus obtains an image by photographing the object with performing pre-emission of the electric flash (the image is referred to as a pre-emission image). Then, a reflected light component (referred to as reflected light data) is found based on a difference between the non-emission image and the pre-emission image. Then, an emission amount of a main photographing (a main emission amount) is obtained according to the reflected light data concerned. And the image pickup apparatus photographs with performing main emission of the electric flash according to the main emission amount concerned.
For example, a block integration value is generated as the reflected light data by integrating luminance values in image areas (blocks) of each of the non-emission image and the pre-emission image. Then, an object weight is obtained for an object area according to the luminance difference between the block integration values, and the emission amount that makes the object be proper luminance is calculated in consideration of external light at the time of the non-emission photography.
When the main emission amount is found in such a manner, the emission amount corresponding to brightness of an object is found wherever the object is positioned within a range to which the pre-emission light reaches in the image (see Japanese Laid-Open Patent Publication (Kokai) No. 2014-98859 (JP 2014-98859A)).
However, when there is a strong light source like a neon lamp (referred to as a high-intensity light source) beside an object, the object and the high-intensity light may be included in the same block depending on a photographing field angle. In such a case, the brightness of the object is determined to be brighter than the actual condition, and the main emission amount is estimated less. As a result, the object becomes dark in the image.
Although it is possible to increase the number of block partitions in an image to reduce an effect of a high-intensity light source, a calculating amount becomes huger as the number of block partitions increases.